MATLAB: Does “hdldispmdlparams” return model parameters when “gcb” is passed in

HDL Coder

I am trying to display the parameters of my HDL block using the following command:

>> hdldispmdlparams(gcb)

Why is the function returning model parameters instead of the parameters for the block that is being passed in?

Best Answer

The function 'hdldispmdlparams' always displays model parameters. A block handle is accepted as an input, but the function will output the parameters of the model that contains the block handle being passed in, and not the parameters of the block itself.

The function 'hdldispblkparams' should be used instead to display HDL block parameters.

Related Solutions

MATLAB: Change “current block”/gcb/gcbh programmatically

Is it not possible to change the code to use block path (string such as 'myModel/Gain') instead of gcb or gcbh? This would be the most straightforward thing to try. If you cannot do this for various reasons:

How do you get the value of hBlock? If you are hard coding it as a variable (by specifying a number) there could be two issues with this:

As this documentation says, You can use the block handle in subsequent calls to get_param or set_param. If you examine the handle, you can see that it contains a double. Do not try to use the number of a handle alone (e.g., 5.007) because you usually need to specify many more digits than MATLAB displays. Instead, assign the handle to a variable and use that variable name to specify a block. Use getSimulinkBlockHandle to get the handle to a block.
Using hard coded values might result in breaking of logic since Simulink can change the handle to the block every time the model is loaded/opened. For e.g it could be 16.0001 now. If I close and open the model again, it maybe different.
I am guessing the equality test might fail because you are trying to compare two floating point numbers.

For e.g. if I do this, it seems to work:

%Open demo model
vdp
%Set Mu block as selected
set_param('vdp/Mu','Selected','on')
%Get Handle to the block
hBlock = getSimulinkBlockHandle(gcb)
%Compare handle value to gcbh
isequal(hBlock,gcbh)

If you run this code mutliple times (each time clearing workspace and closing the open vdp model), you can see the value of hBlock keeps changing.

MATLAB: Do I get output of all zero values from the generated model using HDL Coder R2017b

This is typical behavior when generating VHDL code for a subsystem. By default, the generated model inserts delays in the model to account for hardware implementation on an FPGA. Notice the output in the Command Window upon generating code from such a subsystem:

### Starting HDL check.
### The code generation and optimization options you have chosen have introduced additional pipeline delays.
### The delay balancing feature has automatically inserted matching delays for compensation.
### The DUT requires an initial pipeline setup latency. Each output port experiences these additional delays.
### Output port 0: 23 cycles.

When the HDL code is implemented in hardware, we cannot expect correctly computed values until after a certain amount of time steps. In the attached example, notice that increasing the simulation time to 50 seconds and then generating HDL code will result in a generated model that will show the expected output after 23 cycles have elapsed.

Best Answer

Related Solutions

MATLAB: Change “current block”/gcb/gcbh programmatically

MATLAB: Do I get output of all zero values from the generated model using HDL Coder R2017b

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